Macfie holm



July 11, 1939. J, HOLM 2,155,253

CARTRIDGE FOR THE GENERATION OP GAS PRESSURBS Filed June 18, 1937 JOHN MACF'IE HOLM, INVENTOR.

A TTORNEY.

BEST AVAILABLE COPY gen per gram, does not deposit carbon on combustion; and, in general. deposition of carbon will not occur if the total oxygen-deficiency oi the composition does not exceed about 0.35 gm. oxy- 5 gen per gram composition: the. limiting value or the permissible oxygen'.deilciency dependingtto some extent on the nature as well as thecompositions oi the binder. Guanldine nitrate is a substance which. when compacted by pressure. is incapable oi supporting its combustion when ignited locally at atmospheric pressure. or even undervery considerably increased pressure: and which is characterisedby an even lower oxygen-deficiency than nitro-' guanidine (0.262 gm. oxygen per gram). Mix

tures of nitroguanidine and guanidine nitrate containing more than about 20% guanidine nitrate can be satisfactorily compacted by the use 01 substantially lower pressures than are neceasary for compacting nitroguanidine alone; and compacted mixtures containing nitroguanidine and guanidine nitrate iorm especially useiul charge elements for the purposes oi the present invention. when guanidine nitrate is employed as the binding agent, very considerable quantities may if desired be introduced: so that charge elements having very considerably higher minimum ignition pressures than nitroguanidine itself may thus be obtained. By employment of a successionoi contiguous charge elements 01! increasing guanidine nitrate content, it desired in conjunction with a final charge element oi compressed guanidine nitrate either alone or associated with a carbonaceous ingredient, extremely high preesures may be built up very slowly. and with the intermediate development of maximum pressures only slightlyin excess or the final pressure.

Ittwo ormore charge elements prepared in accordancewiththepresentinventionaretobe flusedinsnccessiomitisoiparticularadvantage thattheproportionoithebindlngagentshould' besoadiustedwithrespect'toitseflectonme minimum ignition pressure oi. the element. that thepressm'eatwhichagivenchargeelement 4g becomes capable oi supporting its own combustionislesathanthatatwhichthesucceeding charge element becomes capable of sell-propagating ccmbusticn under the operating condi- Itisslsoodparticularadvantagethattheminimumignitionpressureotaparticularchargeelementshouldnotbeccnsiderablyexceedingduringthecombustionoitheprecedingelementsoi thetraln.

It will be understood that there is used, in

ing application Serial No. 80,630. died January matured into Patent Humwaxes. resins, gums. carbohydrates. tats and the like. or other colloidal or non-colloidal substances. pretersblythoseotanatureastopermitthe rormation s or compact elements when admixed with nitroany significant carbon deposition on combustion of the charge element is to be avoided.

I may also employ as a binding agent nitrocoliilloae, gelatinised-.with an inert gelatiniscr,

and/or a volatile solvent.

"Unlike the other binding agents to which I .have referred, gelatinised nitrocellulose diminishes the minimum pressure at which compacted nitroguanidine can be ignited, consequently the use in a train of elements containing succcsslvely decreased proportions of nitrocellulose yields a series of charge elements having successively higher minimum ignition pressures.

In preparing these charge elements, however, the proportion of gelatinised nitrocellulose ainployed is less than that which would render the charge element capable oi supp' ting its bustion when ignited locally at pressure and temperature, 1. e., less than about 7.5% when used as the sole binding The presence ot other binding agents may row the use of a somewhat larger proportion of scintinised nitrocellulose. when making such nitrcgelatinised-nitrocellulosc composb tions. it is particularly important that the ch elements should be compacted to a bulk rise-sit";

greater than about 1.2 gm/ml. in order to avoid,

the risk oi an exc' 'f'ively high rate of combus- I! desired, a proportion of gclstiniscil nitrocellulose may be included in a charge cicm -nt comprising nitroguanidine and 2. binding otthe kind that raises the minimum i mi) pressure ct nitroguanidine, in order to facilitate binding Instead of nitrocellulose, we may use niiro starch.-nitrodextrin or nitro-algin to produce similar eflect. or any similar colioidabic appreciable residue. The charge cleaner. prising the present invention, when on... der the increased pressure necessary for their ignition. are substantially ashloso. end produce a satisfactorily high permanent ass color-no,

which may exceed 700 cc. per gm. calculates parts of ,the drawing. the paper shell i is standard unlined I! bore paper shot 1121 o .0 having a metal base 2. a recessed cardboard base-wad s and a cap chamber 3 containing the cap I. A venting hole I is provided in the oi the cage near the base 0! the cartridge, thus atmospheric BEST AVAlLABLE COPY ieequivslenttoansmssesslyielddabmt I35 mL/sm. st stmospheric pressm'eand s temeeratureodlO'O. Thetotslehsrseinthecsrtriage is 17.0 sm., giving a loadins density oi @412 ns/ml. in the testins apelement of s compacted pellet ot a 100:5 gusnidinezacetone-soiuble cellulose acetate positionlcadedincontactwiththe 1.23m. or Ardeer cordite. The bulk density sad 3 ebout 000 ml/sm.st atmospheric prezsore and otemperstureoim'c. Thetotaichsrseinthe certridseis'mmsivinsalosdimoidflfl fashion. 'Ihebnlkdemitysnddiameteroiths pelietsreiMm/mLsndmmm. Whenthis cartridzeisiisedinthesppsrstmdescribedsbove, amaximmnpressnseolahoutlmlhlsmlnis developedinapprouimstelydimtheiinsl pressmebeinsabontidOOb/sminJhelsttsr beinsequinlenttoanamelflyieldodabont filbmilmstatsnospheriomesnn'esndwc. l'hetotsiehsrsemtheartrkheislt'll qmlegaloadinsdensityoiJ1'Im/mLintheahove eppnrstus.

Inthisexsmplqthemethodoiloadincsnd 2;. the preliminary gas-aenerstin: elements etc the ssme es in lxsmple 1, except that e 1.6 oi Ardeer cordite is employed. Toie sss-senerstins elements develops a.

01 lbOi-lt 260 111/8 1. in. and i2. .11? i sition, the bulk density snd diameter 02 1.80 sin/ml. and 13.2 mm. reehsrse element is loaded in the c t2" in contsot with the disc of ct csse being closed by a thin Gelltaleis. secured by usual typo oi onetime tom the this composition the gem we.

the solution incorporated nitrcsusnidine. The oczefew' is compacted in a die, and the pellets are a. inanovenioraiewdaysst3M0Q When tested in the closed veceel, 6.125 carter develops s. maximum pressure oi about 537$ 13M.

tely seconds, the time; pres water, snd di ded C. v sm.. sivins s losdin: density 02 when tired in the closed vessel.

l'mmple 6 The preliminsry sac-generatingemee the ssme as in the preceding exnmpine, of the disc 0! Ardeer cordite 1.1 111a system of gee-gwemtim elem produces a pressure of 170 Ih/eq. in. in 52pm mstely 1 sec. and I. final oi about 12.2 lbs./sq. in. Two contiguous charge elements in. accordsnce with the present invention are a: in the m. the met 01' these, to the of Ardeei' cordite. weighing 7.0 ems. end we in: of nitsogusnidine compacted with 2 or. m weixht at s resinous material containing poly merised methyl methacrylate and dihetyl pmhei ate in the proportion :10. This chemo ole ment isprepsred by a dome from the finely divided nitmmnidine and. en nceinne solution oi the said rctinous me-compactedmixture of cone! weights c. divided nitrosuanidine and menidiee at In this case no voistile metexiei 15 eal to the compnctinl, which is effected by alone. The density oi the compacted is 1.47 m/ml. and the diameter 16.2 mm.

pressure st which this second c element will m te its combustion is what in excess oi 080 lbs. per eezzore main. csrtrldseproducesamaximm "sci? lbs. per sq. inch in about 43 memes, psesanehelnsiiwibepereeiceh. psemm'e corresponds to an average gas eve stmosphericmessm'esndoil' C.

dsmsnysppsrentsndwidaydiiiemn mate of this invention may be mad depsrtinsiromthespiritthereciitio derstoodthstldonotlimitmzmclito loin essmples or descriptions 'cstedintheiollowins pstent cleime.

I claim: i. In s combustion charge for the slow genera BEST AVAILABLE COPY charge elements. one oi which is incapable of 3 supporting itsown, combustion when ignited locelly at atmospheric pressure bymeans ineiiective to heat the whole oi it substantially above atmosphcric temperature but capable oi supportingits" own combustion when ignited under the pressure ccneratedbythecomhustionoia precedingelewent under the conditions. at operation. a comhustible element comprising compacted nitroguanidineandabindinglgcnt.

3. The invention oi claim 2, in which the nitroguanidine is in admixture with a non-hygroscopic binding agent.

4. The invention of claim 2, in which the'bindtug agent is free oi solid residue upon combustion of the charge. I

5. The invention of claim 2, in which the hindlug agent is capable or supporting its own comhustion.

8. The invention of claim 2, in whichthe binding agent has a lower oxygen deficiency than 7; The invention of claim 1, in which the nitrogunnidineisinadmixturewlth abindingagent comprising a carbonaceous ingredient.

8. The invention of claim 1, in which the nitrosuanidine is inadmixture with a binding agent 'ccmprisng acetone-soluble cellulose acetate.

9. Acombustionchargeiortheslow'generation of gas pressure an arrangement in cerialorder oiapluralityotchargeclementsin isnitionrelationshipwitheachotheratleastone oi which supports its owncosnbustion when celly ignited under atmospheric pressure by meansinsumcienttoheatthewholeottheelementtoatemperatnresubstantiallyabove atmos phoriqandatlastoneotwhiohdoesnotsur.

i crtitsowncombmtionwhensubiectedtosuch ignition means at atmospheric pressure and comprisescompactednitrog'uanidine.

10.Acombustionchargei'orthe slowgmerw ticnotgaspressurecomprisinganarrangement in cerialorderoiapluralityoinon-hysroscopic charge element in ignition relationship witheachotheratleastoneotwhichsupportaits ownwhen locallyignitedunderatso o ph'ericpressm'ebvmeansttoheat the'wholeottheelementtoasubstentiallyaboveandatleastcneo! whichdoesnotsuppos'titsownwhen subjected tosnch ignitionmeansat'atmospheric pressureandeomprlsesnitroguanidineoompactedwithabindingm 11.'1he inventionoi'claimillinwhiehthe charge'element containnig'nitmgnanidine iso! such compositim that its negative ouygen bal-' encedoesnotexceedabout-ilztmmgmia'minvmorenmiomm'th with each other in which eech element 512.

- ments..excluding the first, comprises cc ctce prising nilil' llanidine exceeds 20% of! the w guanidine in such a proportion that the or "on binding agent is a colloideble nit-mien eezize. drate in the colloid condition.

18. Ibo-invention or claim 1c in bindingagentlsacolloid.

14. The invention of cleixn 1o binding agent is guanidine lb. The invention of clclsn it) in 3., binding agent is gelatinised nitrccciluie 10. The invention of cleim 19 in em binding agent. is acetone-eolucie cclluic- 17. The invention of claim .10 in ment comprising nitroguoenidineie one a density not less than 1.3 grams pm an 18,. A combustion charge for sic tionkot' gas pressure comprlcing'en in order of a plurality 02 no groscopic charge elements in ignition re its combustion when locally twice the pressure produced by the combustion hi all precedingelements under the conditions c ation, but is incapable of supporting its on s bustion under the pressure at which the ham ately preceding element first supports c combustion, and in which at least one oi the nitroguanidine. 19. The invention of claim 10 in which portion of binding agent used in the element e oitheelement.

20. The invention 01' claim 10 in which the niu'mdilie is associated with a binding agent having a higher oxygen deficiency than ultra deficiency of the element as a whole (ice-z not ex ceed about 0.35 gram oxygen per gram.

21. A combustion charge tor the slow r tion of gas pressure comprising an siren mospheric pressure by means mouths-lent to the whole or the elements to a temp-cream stantially above atmospheric, and o. s V which does not support its own subjected to such ignition menus at same pressure and comprises nitrcgunniem cc. ed with a binding agent comprising having a higher omgsin a than nitroguanidine' and inccmbio ci 5: ing its own combustion out oi contact 22. A combustion charge 101' the slow Hon 0! gas pressure comprising on men in serial order of a plurality of nowhm ashless charge elements in ignition relate-- with each other at least one or which memes 22-2 own combustion when locally-ignited under mospherlcpressurebymeanainsuE-eient to h thewhole ot the element to a temperature eccstantiaily above atmospheric, and at least one of which does not support its own combustion hen subjected to such ignition means at chino pro-lire and nitrcguzuilslihe comp wltha binding agent compnehag geinti tmoellulose up to 7.5% o! the weight oi elemmt.

BEST AVAlLABLE COPY cnn'm'xcam or comcnon. Patent Io. 2,1655263. .m 11, 19 9.,

' Jami mom now.

It in hereby certified that error appeare 1n the printed spaciiieaizimz cm above mflered patent requiring ccrrecticn la follows 2 1 001mm, line 52, tcrthe word "exceeding" read exceeded; page A, firat mm m, nae uh, mph 1;, tor "1m; ga./n1.' read 1.1m @Jmlhg an. acid netter e Patent would be read with ma correction mmmin am can nay contortc the record 01 the can in the Patent. office-O 81M 8 led-10d MI 5th day of Septdei, A. D. 1959.

Henry Van Afscials, (fled) Acting Qcmiccionor or? Pmwzzs, 

